Electric meter.



N0.'796, o37.' y PATENTED AUG.1,1905.

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ELECTRIC METER.

APPLICATION rILnn JULY 11. `1901.

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l Q:D'LHWANl v .ELECTRIC METER.

' APPLICATION FILED JULY 11. 1901.

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, ELECTRIC METER.

Specification of Letters Patent.

Patented Aug. 1, 1905.

Application filed July 11,1901. Serial No. 67,813.

To a/ZZ whom it may concern:

Be it known that I, THOMAS DUNCAN, acitizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a certain new and useful Improvement in Electric Meters, ofwhich the following is a full, clear, concise, and exact description,reference being had to the accompanying drawings, forming a part of thisspecilication. y

My invention relates to electric meters for measuring the power insystems of electrical distribution. Y

In a copending application, Serial No. 66,954, filed July 3, 1901, Ihave disclosed a meter that has as its salient features, first, theprovision of step-by-step adjusting'means whereby the rate of operationof the meter for a'given load may be varied, whereby the meter may becaused to totalize at a rate ac-l cording to the price agreed upon withthe consumer, the meter thus constituting a prediscount-meter; second,the provision of auto.

matically-operated means for governing the rate of operation of themeter, whereby the meter may be caused to operate at different rates ofspeed according to the load, whereby the consumer may be charged at anincreased rate for current that is intermittently consumed above anormal maximum, this automatically-operated means preferably including agraded or step-by-step device for effect- .ing a step-'by-step increasein the torque of the meter-that is, as the excess in load increases thenormal torque is correspondingly ent ratesof discount-that is, themeters when provided with scales indicating kilowatt-hours or othermeasuring units maybe caused to register different amounts for a givenquantity of current, which is a way of aording consumers theirrespective discounts.

I am enabled to have the operation of the meter adjusted in a manner tohave the meter indicate that which the consumer is to bel charged for.lThe reading-scale may, if desired, be marked to indicate thekilowatthours, the adjusting means being provided to produce anoperation of the counting-train of the instrument that need notnecessarily indicate the exact energy or load, but the quantity ofenergy or load that the consumer is to be charged for, the readingindicating the total' actual power consumed less the prearrangeddiscount. For example, the meters may be equipped with step-by-stepadjusting devices providing for five, ten, fifteen, twenty` andtwenty-five per cent. discount. One consumer may not be given anydiscount. His meter will then indicate the true reading inkilowatt-hours of the energy consumed. Another consumer may be given[ive per cent. discount. Supposing that he has consumed one thousandkilowatt-hours, his instrument will indicate'a charge for nine hundredand fifty kilowatt-hours. Another consumer who uses ten thousand or morekilowatt-hours may be given ten per cent. discount, and for the tenthousand kilowatt-hours consumed his meter will indicate a charge fornine thousand kilowatt-hours. By this arrangement the keeping ofaccounts is greatly simplified, as the consumers are charged accordingto the readings of their meters, each instrument then taking cognizanceof the particular consumers discount.

In my said copending application I have provided a rheostat andautomatic means for cutting the resistance thereof out of circuit withthe armature of the meter as the current in the working circuitincreases above the normal maximum, whereby the rate of registration perunit of energy or load is increased whenever the load upon the system isincreased above the normal maximum. This feature is of particularutility in systems where motors that are frequently started are used-as,for example, in hoistingwhere the consumer obviously should be chargedin excess of the normal rate where excessive demands are intermittentlymade upon the system.

In the said copending application I have included a prediscountresistance in series with the rate-changing rheostat and themeter-armature, the prediscount resistance serving to eect a fixedpercentage reduction in the rate of registration of the instrument inaccordance with the discount the consumer is to receive from the chargefor the power supplied to him. In my present application I include thediscount resistance in circuit with the armature alone, while therate-changing resistance or rheostat is included in circuit with afieldwinding which is preferably an auxiliary field-winding, circuitthrough which is completed each time the current exceeds the normalmaximum.

In my said copending application I have provided two countingmechanisms, one for recording the power consumed when the current iswithin normal limits and the other for ,recording the power consumedwhen the current exceeds the normal limits, and have provided the saidcounting mechanisms with a rocking frame-carrying gearing, which isswung into engagement with one countingtrain or the other through theagency of an electromagnet that is operatively energized each time thecurrent exceeds the predetermined norfmal maximum, this gearing being inengagement with the rotating element or shaft of the meter.

In my present invention I employ a reciprocating adjustment, the shaftof the meter being preferably swung into engagement with onecounting-train or the other. An electromagnet is provided for shiftingthe shaft into engagement with that counting-train, the abnormalcounting-train, that records the power consumed when the current isabove the normal maximum. This electromagnet is preferably in serieswith the rate-changing rheostat or resistance and the supplementalfieldwinding whose magnetizing influence is controlled by therate-changing resistance.

I will explain my invention more fully by reference to the accompanyingdrawings, in which- Figure l illustrates a system of direct-cu rrentdistribution, the meter being diagrammatieally indicated in elevation.Fig. 2 is also a view of a system of direct-current distribution, thecounting-train being illustrated in detail, the dial-plate beingremoved.

Like parts are indicated by similar characters of reference throughoutthe figures.

I have illustrated asystem of direct-current distribution and acommutated motor-meter; but the invention is equally applicable to othersystems of electrical distribution and to meters of other forms. 1

In Figs. 1 and 2 the generator 1 supplies cu rrent to thetransmission-mains 2 2. These mains convey current to translatingdevices, such as motors, a motor 3 of well-known type being illustratedin Fig. 1, this motor being connected in circuit with supply-conductors4 4. 'A meter 5 is associated with the consumer-s supply-circuit 4 4,the meter in this instance employing a field-winding divided into coils6 6, in series with one of the conductors 4, and an armature 7, inbridge between the mains 4 4, a commutator 8, with brushes 9 9, beingprovided for including the armature in circuit. rlhe armature is mountedupon a shaft 10, at the lower part of which is a damping-dish 11,arranged within the fields of the permanent magnets 12 12 to securerequisite damping effect.

In order to adjust thel torque of the meter to conform to theprearranged cost of the current, I preferably include a resistance 212%,that may be termed a discount resistance, in series with the armature,this resistance being provided with a plurality of discount-buttons thatmay be suitably marked to indicate various discounts. A switch-arm 14may be swung into engagement with any of the buttons to include more orless of the resistance 13 in circuit with the armature. This feature ofthe apparatus is fully set forth in my copending application, and I willnot, therefore, describe it further. 'Ihe meter is also provided with atorque-:uljusting resistance 15, divided into sections having terminalcontacts 16. 'Ihis resistance is designed to be altogether includedpreferably in series with the supplemental held-winding divided intocoils 17 during the presence of normal current in the system. As thecurrent in the system is increased beyond the normal maximum, thisresistance 15 iscut out of circuit step by step. By means to bepresently set forth the total resistance 15 is cut into circuit when thecurrent exceeds the normal maximum, the resistance decreasing in amountas the current increases beyond the normal maximum, the said resistancebeing totally removed from the circuit when the current in the system isbelow the normal maximum. 'Ihe auxiliary winding 17, being in serieswith the rcsistancc 15, is also removed from circuit when the current inthe system is below the normal maximum. When this resistance is cut intocircuit, the coils 17 establish another lield, thereby increasing thetorque of the instrument and effecting a corresponding increase in therate of registration per unit of energy or load.

rIhe means that I preferably employ for cutting the resistance 15 intocircuit and decreasing the amount thereof subsequently consists of asolenoid or electromagnet 18, that is included in series with thetranslating means 3, the core of the solenoid being provided with an arm19, that forces the spring-terminals 16 together as the core of thesolenoid is drawn intothe helix thereof,the attraction of thehelix ofthe solenoid for its core increasil'lg as the abnormal current withinthe distrilmtion-circuit increases. The arm 19 is connected with one ofthe transmission-mains,while the resistance 15 and the auxiliary coils17 are connected with the other main, so that as soon as this arm isdrawn into contact with one of the terminal springs 16 circuit throughthe resistance and the supplemental field-coils 17 is closed. For

example, if the meter 3 is designed to operate normally when the currentremains within the normal maximum of one hundred amperes and if thecurrent exceeds this value by tive per cent. thecore of the' solenoidwill be drawn sufficiently within its helix to bring the two upperresistance-terminals 16 into contact, thereby cutting out the firstsectionv of the resistance 15 and causing an increase of iive per cent.in thenormal torque of the meter, whereby the rate of registration perunit of energy or load is increased. If the current in thedistribution-circuit should increase seven and one-half per cent. abovethis normal, then the three upper resistance-terminals 16 are broughtinto contact upon the further attraction of the solenoid-core, vwherebythe two upper sections of the resistance 15 are short-circuited and anincrease of ten per cent. in the normal torque of the meter effected.Thus the sections of the resistance 15 are successively cut out orshunted out of circuit as the current increases above the maximum,therebyincreasing the strength of the field, due to the auxiliarywinding 17, and correspondingly increasing the torque of the meter. Thecore of the solenoid is preferably adjusted, by means of springs 20', toprevent the same from being drawn within the solenoid-helix while normalcurrent only is present upon. the line.

I prefer to record the. excess rate upon a different counting mechanism,and on this account I provide each meter with two counting-trains 20 and21, the counting-train 2() constituting the normal counting-train,whilethe counting-train 21 constitutes the abnormal counting-train. To elfectthis alternate engagement of the rotating element or shaft of the meterwith one or the other of the counting-trains, I provide the upper end ofthe shaft with a worm-thread that is adapted for engagement with a wheelof one or the other of the counting-trains. I mount the upper bearing 22of the shaft in a sliding or reciprocating support 23, which is moved toone of its extreme positions by a spring 24 when the current in thesystem is within the normal limits. The sliding support'is connectedwith the core or armature of the solenoid or electromagnet Q5, the helixof said magnet being in series with the resistance 15 and auxiliaryfield-coilsl?. When the current in the system exceeds the normalmaximum, the sliding support 23 is moved toward the right against theforce of the spring 24:, whereby the upper bearing of the armatureshaftis moved to bring the shaft that was previously in engagement with thenormal counting-train upon the left into engagement withthe abnormalcounting-train upon the right.

While I have herein shown and particularly described the preferredembodiment of my invention, it is obvious that changes may readily bemade without departing from the spirit thereof, and I do not, therefore,wish to be limted to the precise disclosure herein set forth;

'Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The combination with a system of electricaldistribution, of a metery receiving current therefrom, normal andabnormal counting mechanisms, a rotating element of the meter providedwith a thread adaptedfor engagement with one or the other ofthecountinganism, and` electromagnetic means for' operating the said switchwhen the current in the system exceeds the normal maximum, substantiallyas described.

2. The combination with a'system of electrical distribution, of av meterreceiving current therefrom, normal and abnormal counting mechanisms, arotating element of the meter provided'with a thread adapted'forengagement with one or the other of the'counting-trains of saidmechanisms, the said rotating element being provided with a bearing, areciprocating support for the said bearing, means for normallymaintaining the said support in one position to engage the rotatingelement of the meter with the normal counting-train, an electromagneticmechanism serving when energized to move the said rotating element intoengagement with the countingtrain of the abnormal counting mechanism, aswitch for energizing the said electromagnetic mechanism,electromagnetic meansA for operating the said switch when the current inthe system exceeds the normal maximum, and means whereby the latterelectromagnet is prevented from operating the switch controlled therebyuntil the current exceeds the normal maximum, substantially asdescribed.

3. The combination with a system of electrical distribution, of a meterreceiving current therefrom, normal and abnormal counting mechanisms, arotating element of the meter adapted for operative engagement with lone or the other of the said counting mechanisms, automatically-operatedmeans for shifting the said rotating element into engagement with one orthe other of the said counting mechanisms, and means whereby therotating element is prevented from being shifted from engagement withthe normal counting mechanism until the current in the system exceedssaid meter, means for varying the magnetizing eect of the auxiliaryfield-winding, and electromagnetic means' governed by the current of thesystem governing the aforesaid means and serving to increase themagnetizing effect due to the said auxiliary field-winding upon anincrease in the current of the system, substantially as described.

5. The combination with a system of electrical distribution, ofa meterconnected therewith, a supplemental field-winding for the said meter,means for varying the magnetizing effect of the auxiliary field-winding,electromagnetic means governing the aforesaid means and serving toincrease the magnetizing effect due to the said auxiliary field-windingupon an increase in the current of the system, and means whereby thesaid electromagnet is prevented from operating until the current withinthe system exceeds a predetermined normal maximum, substantially asdescribed.

6. The combination with a system of electrical distribution, ofameterconnected therewith, a supplemental field-winding for the saidmeter', a rheostat, a switch, an electromagnetic mechanism for operatingthe switch to include the said rheostat in circuit with the auxiliaryfield-winding and thereby adjust the magnetizing effect thereof, thesaid electromagnetic mechanism serving to exclude portions of theresistance from circuit with the auxiliary field-winding as theenergization of the said electromagnetic mechanism is increased, wherebythe torque of the meter is increased as the current in the circuit isincreased to produce an increased rate of registration by the meter,substantially as described.

7. rlhe combination with a system of electrical distribution, of a meterconnected therewith, a supplemental held-winding for the said meter, arheostat, a switch, an electromagnetic mechanism for operating theswitch to include the said rheostat in circuit with the auxiliaryfield-winding and thereby adjust the magnetizing effect thereof, thesaid electromagnetic mechanism serving to exclude portions of theresistance from circuit with the auxiliary field-winding asthe-energization of the said magnet is increased, whereby the torque ofthe meter is increased as the current in the circuit is increased toproduce an increased rate of registration by the meter, and meanswhereby the said eleetromagnetis prevented from operating until thecurrent in the system has increased beyond the predetermined normalmaximum, substantially as described.

8. In an electric meter,the combination with normal and abnormalcounting mechanisms, of a rotating element of a meter adapted foroperative engagement with one or the other of the said countingmechanisms, automatically-operated means for shifting the said rotatingelement into engagement with one or the other of said countingmechanisms, and means whereby the rotating element is prevented frombeing shifted from engagement with the normal counting mechanism untilthe current in the system exceeds the normal value, substantially asdescribed.

9. In an electriemeter,the combination with a supplemental field-windingfor said meter, of means for varying the magnetizing effect of thesupplemental field-winding, and electromagnetic means governing theaforesaid means and serving to increase the magnetizing effect due tothe said auxiliary field-winding upon an increase in the current of thesystem, substantially as described.

l0. In an electric meter, the combination with asupplementalfield-winding for the said meter, of means for varying the magnetizingeffect of the auxiliary field-winding, electromagnetic means governingthe aforesaid means and serving to increase the magnetizing effect dueto the said auxiliary field-windingupon an increase in the current ofthe system, and means whereby the said electromagnet is prevented fromoperating until the current within the system exceeds a predeterminednormal maximum, substantially as described.

In witness whereof I hereunto subscribe my name this 23d day of May, A.D. 1901.

THOMAS DUNCAN.

Witnesses:

GEORGE L. CRAGG, HERBERT F. OBERGEELL.

